
The big picture: Fungi are essential for ecosystem function
- 100,000 species described
- estimated 1.5 million species
- diverse size, morphology and habitats
- Heterotrophic: eat via absorption
- parasites, decomposers, mutualists
- recycle nutrients via decomposition
- Cell walls made of chitin
- mushrooms are only a part of the body
- filaments belowground for absorption

Chitin and Heterotrophs → Animals & Fungi


Fossil Fungi


- Oldest fungal fossils appear ~900 mya
- split from aquatic eukaryotic ancestor 1 bya(?)
- Fossils of fungal spores found in Wisconsin dated to 460 mya
- suggests origin of land-based fungi
- Fungi and plants moved onto land around same time
- what was the benefit for fungi?
- helped vascular plants invade the land!
- mycorrhizal symbiosis @ 405mya during Devonian period
All fungi share traits related to nutrition
- Heterotrophs: absorb nutrients from environment
- decomposers: break down dead things
- parasites: absorb from host
- mutualist: absorb/share with host
- Use enzymes to break down compounds
- diverse enzymes for diverse food sources
- secreted outside the cell (extracelluar)

Fungal derived enzymes and humans: Cellulase

Fungal derived enzymes and humans: Statins

Fungal body plan: Not-motile and mostly multi-cellular

Most hyphae divided into cells by septa


Specialized hypae in mycorrhizal fungi
- Specialized hyphae for feeding on live animals
- hoops that can snare prey
- Specialized hyphae that allow extraction of nutrients from plants
- Mutualistic fungi have branching hyphae they use to exchange nutrients with plant hosts
- Arbuscules invade cell walls

Mycelium: huge surface and volume for absorption


Mycorrhizal fungi: sharing with plants
- ~80-90% of plants have association with fungus
- fungi grown in/around plant roots
- share what resources?
- how much sharing is not known
- 2 main types:
- Ecto and Arbsucular mycorrhizae
- Association now key for plants to thrive
- fungi more efficient @ nutrient uptake

Fungi rule the world: plants evolution linked to symbiosis

Fungal life cycles (Haplonic)
- Life cycles can be complex
- spores are produced sexually or asexually
- spores and nuclei of hypae are haploid (1N)
- Lots of spores are produced
Sexual Reproduction:
1. Plasmogamy:
2. Karyogamy:

Fungal life cycle: basic

Fungal lineages (no longer clean groups)

Fungal lineages (no longer clean groups)

Fungal-animal mutualisms


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